JP2001172397A - Method for producing resin composition pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing pellets of a resin composition which excels in handling characteristics of a polyamideimide resin and charging stability to an extruder and, simultaneously, can efficiently produce pellets in melt kneading the polyamideimide resin with another thermoplastic resin to pelletize the resulting melt. SOLUTION: The method for producing resin pellets comprises melt kneading granules obtained by mechanical granulation of a polyamideimide resin powder with another thermoplastic resin and pelletizing the melt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing pellets by melting and kneading a polyamideimide resin and another thermoplastic resin, and more particularly, to a method excellent in handleability and supply stability to an extruder. The present invention relates to a method for producing a resin composition pellet capable of producing a pellet efficiently.

[0002]

2. Description of the Related Art Polyamide-imide resins are excellent in heat resistance, mechanical strength, electrical properties, chemical resistance, flame retardancy, etc., and are used as various mechanical parts, OA equipment parts, films, varnishes and the like. . However, polyamideimide resins are suitable for use in varnishes and cast films, but are inferior in moldability, and most of them are difficult to melt-mold such as injection molding and extrusion molding. Therefore, in order to manufacture a molded article using a polyamideimide resin, a compression molding method is mainly employed.

[0003] Conventionally, by blending a polyamide-imide resin and various thermoplastic resins, moldability and processability have been improved.
It has been proposed to provide a resin composition having an excellent balance of heat resistance, mechanical strength, and the like. For example, a resin composition comprising an aromatic polyamide-imide resin and a polyester resin (JP-A-7-207157) and a resin composition obtained by melt-kneading an aromatic polyamide-imide resin and a polyphenylene sulfide resin (JP-A-6-200154) Publication), a resin composition comprising a polyphenylene sulfide resin, a polyamideimide resin and an epoxy resin (Japanese Patent Laid-Open No.
No. 9-164360). Further, in order to enhance the adhesiveness of a molded article made of a polyarylene sulfide resin, a method of modifying the surface by blending a small amount of a polyamideimide resin has been proposed (JP-A-7-309957).

When such a resin composition is supplied to a molding machine such as an injection molding machine or an extrusion molding machine, each resin component is melted and kneaded with an extruder in advance, and then pelletized before being supplied. To make pellets, supply each resin component and various additives as needed to the extruder, melt-knead,
Pelletizer makes pellets by cold cut, hot cut, under water cut, sheet cut, etc. However, the polyamideimide resin is recovered as fine powder with a small bulk density in the manufacturing process, and is used as a powder for blending with various resins. Therefore, the handling properties are poor and the supply to the extruder is stable. However, there was a problem that the extrusion efficiency was very low.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for melting and kneading a polyamideimide resin and another thermoplastic resin into pellets, which has excellent handleability of the polyamideimide resin and which is supplied to an extruder. An object of the present invention is to provide a method for producing resin composition pellets, which has excellent stability and can produce pellets efficiently.

The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, the polyamide-imide resin powder was mechanically granulated into a granulated product having a large particle size. The present inventors have conceived a method of pelletizing a resin by melt extrusion. By using a polyamide-imide resin granule, a method for producing resin composition pellets excellent in handling properties, supply stability to an extruder, and extrusion efficiency is provided. The present invention has been completed based on these findings.

[0007]

According to the present invention, a granulated product (A ₁ ) obtained by mechanically granulating a polyamide-imide resin (A) powder and another thermoplastic resin (B) are melt-kneaded. Thus, a method for producing a resin composition pellet to be pelletized is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Polyamideimide resin (A) The polyamideimide resin used in the present invention is usually produced from an aromatic tricarboxylic anhydride and an aromatic diamine. It is a polymer in the form of alternating groups. That is, the polyamideimide resin generally has the formula (1)

[0009]

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Wherein Ar is at least one carbon 6
A trivalent aromatic group containing a member ring, R is a divalent aromatic or aliphatic group, and R ¹ is a hydrogen atom, an alkyl group, or a phenyl group. ) Is a resin having a repeating unit represented by ()) as a main constituent unit. A part (preferably less than 50 mol%, more preferably less than 30 mol%) of the imide bond in the formula (1) may remain as an amide bond. The amide bond can be converted into an imide bond by post-curing the molded article after molding.

The polyamideimide resin used in the present invention particularly preferably contains the repeating unit represented by the formula (1) in an amount of 100 mol%, but preferably contains other repeating units in an amount of 50 mol% or less, more preferably 30 mol%
Copolymers containing the following proportions can also be used. As other repeating units, the following formulas (2) to
Each repeating unit represented by (4) can be mentioned. The copolymer may contain one or more of these repeating units.

[0012]

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(Wherein, Ar ¹ is a divalent aromatic or aliphatic group containing at least one carbon 6-membered ring;
Is a divalent aromatic or aliphatic group. )

[0014]

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(In the formula, Ar ² is a tetravalent aromatic group containing at least one carbon 6-membered ring, and R is a divalent aromatic group or an aliphatic group.)

[0016]

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(In the formula, Ar ² is a tetravalent aromatic group containing at least one carbon 6-membered ring, and R is a divalent aromatic group or an aliphatic group.) )
Specific examples of the trivalent aromatic group (Ar) include those represented by formulas (5) to (5).
And groups represented by (8).

[0018]

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Among these, a group represented by the formula (5) is preferable. Specific examples of the divalent aromatic group or aliphatic group (R) include groups represented by formulas (9) to (35).

[0020]

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[0021]

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[0022]

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[0023]

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Among these, the formulas (9), (10),
(11), (16), (17), (29), (23),
The groups represented by (24), (27), and (28) are preferable, and the formulas (9), (10), (11), (20), and (2)
Groups represented by 3) and (24) are more preferred, and groups represented by formulas (9), (11) and (20) are particularly preferred. In the formula (2), specific examples of Ar ¹ include the formulas (9), (10), (16), (17),
(18), (19), (29), (30), and (3)
In addition to the group represented by 5), groups represented by the following formulas (36) to (41) may be mentioned.

[0025]

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In the above formulas (3) and (4), Ar ²
Specific examples include groups represented by the following formulas (42) and (43).

[0027]

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The repeating units represented by the above-mentioned formulas (1) to (4) have different Ar,
One or more corresponding to Ar ¹ , Ar ² , or R may be present. Polyamide imide resin can be prepared by (a) reacting an aromatic tricarboxylic anhydride halide with a diamine in a solvent (acid chloride method), or (b) reacting an aromatic tricarboxylic anhydride with a diamine in a solvent (directly). (Polycondensation method), (c) a method of reacting an aromatic tricarboxylic anhydride and diisocyanate in a solvent (isocyanate method), and the like. Of these, in the acid chloride method and the isocyanate method, in order to compensate for the slow reaction between the aromatic diamine and the carboxyl group, either of them is a method in which either monomer is converted to an activated derivative and polycondensed.

In the acid chloride method of the above (a), 2
More than one kind of aromatic tricarboxylic anhydride halide and diamine may be used, and if necessary, dicarboxylic dichloride and aromatic tetracarboxylic anhydride may be reacted. The reaction is carried out in the presence or absence of a hydrogen halide acceptor such as triethylamine and sodium hydroxide in a polar solvent such as N-methyl-2-pyrrolidone, or in the presence of a hydrogen halide acceptor. The reaction can be performed in a mixed solvent of water and an organic solvent (for example, acetone) that is partially miscible with water.

In the direct polycondensation method of the above (b), 2
More than one kind of aromatic tricarboxylic anhydride and diamine may be used, and if necessary, dicarboxylic acid or aromatic tetracarboxylic anhydride may be reacted. The reaction is carried out with or without N-methyl-2 in the presence or absence of a dehydration catalyst.
-Can be carried out in a polar solvent such as pyrrolidone or without a solvent.

In the isocyanate method (c), two or more kinds of aromatic tricarboxylic anhydrides and diisocyanates may be used, and if necessary, a dicarboxylic acid or an aromatic tetracarboxylic anhydride may be reacted. May be. The reaction can be performed in a polar solvent such as N-methyl-2-pyrrolidone or without a solvent. In this method, the reaction is performed with a strictly defined amount of water, the reaction temperature is controlled in multiple stages, and the generation of the amide group is completed, and then the imide group is generated.If necessary, a catalyst is used. Strictly controlling the molar ratio between the acid anhydride compound and the carboxylic acid compound is an effective means for improving the efficiency of the reaction, controlling the structure of the produced polymer, and controlling the molecular weight.

In each of the above-mentioned methods, monocarboxylic acids such as benzoic acid; acid chlorides such as benzoic acid chloride; dicarboxylic acids such as succinic anhydride and naphthalenedicarboxylic anhydride for the purpose of adjusting the molecular weight or controlling the structure of polymer terminals. Monofunctional compounds such as acid anhydrides; monoisocyanates such as phenyl isocyanate; and phenols can be used. The polymer obtained by each of the above methods can be subjected to heat treatment (curing) to convert the amic acid structure to an imide ring, if necessary.

When the polymerization reaction is carried out in a solvent, the polyamideimide resin used in the present invention is prepared by converting the solution or slurry after the reaction to an alcohol such as methanol, ethanol, isopropanol or the like; acetone, methyl ethyl ketone or the like. Ketones; aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as benzene and toluene;
The resulting polymer is precipitated by treatment using, for example, and recovered by washing. After the completion of the polymerization reaction, the polymerization solvent may be directly removed by evaporation to precipitate the polymer, and the polymer may be recovered by washing with the above solvent. In the isocyanate method, after the polymerization reaction is completed, the solvent may be concentrated to some extent, and then the solvent may be removed under reduced pressure by an extruder or the like.
Thus, the polyamide-imide resin is recovered from the polymerization reaction system. The recovered polyamideimide resin is a fine powder having a weight average particle diameter of less than 100 μm, usually 50 μm or less, and often about 20 to 30 μm.

The polyamideimide resin used in the present invention may be produced by any of an acid chloride method, a direct polycondensation method, and an isocyanate method.
When used for injection molding or extrusion molding, a polyamideimide resin prepared by an isocyanate method is preferably used from the viewpoint of easy control of the structure and molecular weight of the produced polymer. The polyamide-imide resin used in the present invention is a dimethylformamide having a concentration of 1 g / dl at 30 ° C.
Is usually 0.1 to 1.5 dl /
g, preferably 0.12 to 1.00 dl / g, more preferably 0.15 to 0.80 dl / g.

Polyamide-imide resin granules (A ₁ ) The polyamide-imide resin granules of the present invention are obtained by mechanically compressing a polyamide-imide resin powder at a temperature not higher than the glass transition temperature of the polyamide-imide resin. It can be obtained by pulverizing the solid after forming it into a rod-shaped solid. By mechanically compressing the polyamide-imide resin powder, the bulk density of the solid is preferably 0.5 g /
cm ³ or more, more preferably 0.7 g / cm ³ or more, particularly preferably 0.9 g / cm ³ or more. If the bulk density of the solid is too small, it becomes too brittle, and it becomes difficult to obtain a granulated product of a desired size during pulverization. Also, if the bulk density of the solid is too small, even when a granulated product is obtained,
It becomes difficult to maintain the shape when mixing with a thermoplastic resin or a filler or when supplying to an extruder.

The pulverization of the solid can be carried out using a conventional pulverizer. The weight average particle diameter of the granulated product obtained by the pulverization is preferably 100 μm or more, more preferably 300 μm or more, and further preferably 500 μm or more. The upper limit of the weight average particle size of the granulated product is 5 mm (500
0 μm). In many cases, the weight average particle diameter of the granulated product is in the range of 500 μm or more and 3 mm or less. If the weight average particle size of the granulated product is too small, the effect of improving the handling properties is small, and the supply stability to the extruder and the extrusion efficiency are reduced. The bulk density of the granulated product is preferably 0.30 g / cm ³ or more, more preferably 0.35 g / cm ³ or more.
g / cm ³ or more, particularly preferably 0.40 g / cm ³ or more.

Thermoplastic Resin (B) The thermoplastic resin used in the present invention is not particularly limited. For example, polyamide resins such as nylon, 6, nylon 66 and nylon 6/66; polybutylene terephthalate, polyethylene terephthalate, etc. Polyolefin resins such as polyethylene, polypropylene and polybutene; poly (meth) acrylate resins such as polymethyl acrylate and polymethyl methacrylate; chlorine-containing resins such as polyvinyl chloride and polyvinylidene chloride; polyphenylene Polyarylene sulfide resin such as sulfide resin; aromatic vinyl polymer such as polystyrene; tetrafluoroethylene /
Fluororesins such as hexafluoropropylene copolymer, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, polyvinylidene fluoride; wholly aromatic polyester, liquid crystal polyester, modified polyphenylene ether, polyether ether ketone, polyether ketone, polyphenylene sulfide Engineering plastics such as ketone, polyphenylene sulfide sulfone, polyether nitrile, polyarylate, polysulfone, polyether sulfone, polyetherimide, polyimide, polyaminobismaleimide; polyacetal, polyisobutylene, polyisoprene, poly-p-
Examples include xylene, polycarbonate, polyurethane, polydimethylsiloxane, polyvinyl acetate, ABS resin, triazine resin, and modified products thereof. These thermoplastic resins can be used alone or in combination of two or more.

Among these thermoplastic resins, a polyarylene sulfide resin such as a polyphenylene sulfide resin and a thermoplastic polyester resin such as a polyethylene terephthalate resin are preferable. These thermoplastic resins can be used in various forms such as powders, granules, pellets, etc., but in consideration of handling properties and supply to an extruder, extrusion efficiency, etc., they are in the form of granules or pellets. Is preferred.

Filler (C) Various fillers can be added to the resin composition pellets of the present invention, if necessary. Examples of the filler include inorganic fibers such as glass fiber, carbon fiber, asbestos fiber, silica fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, and potassium titanate fiber; stainless steel, aluminum And fibrous fillers such as titanium, steel, brass and other metal fibrous materials; polyamide resin, fluororesin, polyester resin, acrylic resin and other high melting point organic fibrous materials; and the like. As the filler, for example, mica, silica, talc, alumina,
Non-fibrous (granular, powdered) such as kaolin, calcium sulfate, calcium carbonate, titanium oxide, magnetic powder (eg, ferrite), clay, glass powder, zinc oxide, nickel carbonate, iron oxide, quartz powder, magnesium carbonate, barium sulfate, etc. And flakes).

These fillers can be used alone or in combination of two or more. The filler may be treated with a sizing agent or a surface treatment agent, if necessary. Examples of the sizing agent or surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after subjecting the filler to a surface treatment or a sizing treatment beforehand, or may be added at the same time when the resin composition is prepared. When a silane-based coupling agent or the like is blended together with a filler during the preparation of the resin composition, it functions as a kind of compatibilizer.

Other additives (D) In the present invention, other additives other than the above-mentioned fillers include
For example, resin modifiers such as ethylene glycidyl methacrylate, lubricants such as pentaerythritol tetrastearate, thermosetting resins, antioxidants, ultraviolet absorbers, nucleating agents such as boron nitride, flame retardants, dyes and pigments And the like can be appropriately added.

[0042] In the resin composition constituting the resin composition pellets, blending ratio of the polyamide-imide resin and other thermoplastic resin is not particularly limited, moldability, heat resistance, when considering the other properties, polyamide Imide resin is usually 0.5 to 70
%, Preferably 1 to 60% by weight, more preferably 5% by weight.
To 55% by weight, and other thermoplastic resin is usually 30%.
-99.5% by weight, preferably 40-99% by weight, more preferably 45-95% by weight.

When a filler is compounded, the resin component 10
It can be added in an amount of usually 0 to 800 parts by weight, preferably 0 to 500 parts by weight, more preferably 0 to 300 parts by weight with respect to 0 parts by weight. In particular, when an inorganic fibrous filler such as glass fiber is blended as a filler, tensile strength,
A resin composition having excellent mechanical properties such as flexural strength, flexural modulus, and flexure can be obtained. When the filler is blended, the lower limit of the blending ratio can be appropriately determined as desired. However, in order to improve the mechanical properties, it is usually at least 1 part by weight, preferably at least 5 parts by weight, more preferably at least 10 parts by weight.
Parts by weight or more.

Method for Producing Resin Composition Pellets Resin composition pellets can be prepared by equipment and a method generally used for preparing a synthetic resin composition. For example, each raw material component is premixed by a Henschel mixer, a tumbler or the like, and if necessary, a filler such as glass fiber is added and further mixed, and then melt-kneaded using a single-screw or twin-screw extruder, It can be extruded into a molding pellet. A method of mixing some of the necessary components as a masterbatch and mixing with the remaining components, and in order to enhance the dispersibility of each component, crushing some of the raw materials used, mixing and mixing the particle size, Melt extrusion is also possible.

The pelletizing method is not particularly limited.
For example, a molten material is extruded in a strand shape using an extruder, a cold cut method for cutting after cooling, a hot cut method for cutting at an exit of a die, an underwater cut method for cutting in water, and a small extruded sheet. A sheet cutting method for cutting into a rectangular parallelepiped can be adopted.

[0046]

The present invention will be described more specifically below with reference to examples and comparative examples. Methods for measuring physical properties and the like are as follows. (1) Weight-average particle diameter The weight-average particle diameter was calculated based on a particle diameter distribution measured according to JIS K-0069. (2) Fluctuation in extrusion rate Extrusion was carried out by a twin screw kneading extruder of 46 mmφ. At this time, the amount of compound extruded 20 times at 2 minute intervals for 36 seconds was measured, and the variation in extrusion rate per unit time was calculated. did.

Production Example 1 N-methyl-2-pyrrolidone was added at room temperature to a 20-liter reactor equipped with a polyamide-imide resin synthesis stirrer, a thermometer and a gas inlet tube at room temperature while flowing dry nitrogen. Then, 2 kg of trimellitic anhydride was charged. At this point, the water content in the system was 45 ppm. Immediately, 1.81 kg of 2,4-tolylene diisocyanate was added, the temperature was raised from room temperature to 90 ° C. over 30 minutes while flowing nitrogen, and the reaction was carried out at this temperature for 60 minutes. After that, one more 20 minutes
The temperature was raised to 15 ° C., and the reaction was continued for 8 hours while maintaining this temperature. After the completion of the reaction, the polymer solution was halved, and 10 liters of N-methyl-2-pyrrolidone was added to each and diluted. Thereafter, each polymer solution was dropped into 40 liters of methanol, which was stirred at high speed. Each precipitated polymer was subjected to suction filtration, further redispersed in 40 liters of methanol, and filtered. This operation 2
After repeating this process, all the collected products were dried at 200 ° C. under reduced pressure to obtain a powdery polymer. From the infrared absorption spectrum of the obtained polymer, the absorption of the amide group and the imide group was confirmed. In a dimethylformamide solvent having a concentration of 1 g / dl,
The reduced viscosity of the polymer measured at 30 ° C. is 0.22 dl
/ G. The glass transition temperature of the polymer measured by a differential scanning calorimeter (DSC) was 323 ° C., the weight average particle size was 25 μm, and the bulk density was 0.25 g / cm ³ .

[Production Example 2] Granulated product of polyamide-imide resin
A polyamide-imide resin powder having a weight average particle size of 25 μm and a bulk density of 0.25 g / cm ³ obtained in Production Example 1 was rolled using a roller compactor (RCP- manufactured by Kurimoto Iron & Steel Co., Ltd.) equipped with a feed screw and two rollers. 200H) to produce a plate-like solid. The operating conditions of the roller compactor were as follows: roll compression force = 1.3 t / cm ² , roll rotation speed = 55 rpm, roll rotation speed = 2.5 rpm
m, treatment amount = 7.8 kg / h. The bulk density of the obtained plate-like solid was 0.98 g / cm ³ . The plate-like solid is pulverized by a pulverizer to obtain a weight average particle diameter of 600 μm.
m, and a granulated product having a bulk density of 0.45 g / cm ³ were obtained.

[Examples 1 to 3 and Comparative Examples 1 to 3] The components shown in Table 1 were uniformly dry-blended with a tumbler mixer, and then a 46 mmφ biaxial kneading extruder (manufactured by Ikegai Iron and Steel Co., Ltd.
PCM-46), melt extrusion was performed, and the extrusion amount and the fluctuation of the extrusion amount were evaluated. The extrusion temperature was determined in Examples 1-2.
In Comparative Examples 1 and 2, melt extrusion was performed in the range of 280 ° C to 350 ° C, and in Example 3 and Comparative Example 2, the range was 240 ° C to 280 ° C. In addition, the molten material is extruded in a strand shape, and the diameter is 3 m by the cold cut method.
m, a pellet having a length of 3 mm was prepared. Table 1 shows the results.

[0050]

[Table 1]

(Footnotes) (1) PPS: polyphenylene sulfide resin granules (manufactured by Kureha Chemical Industry Co., Ltd., FORTRON KPS; average particle diameter = 50)
(2 μm) PET: polyethylene terephthalate resin pellets (Toyobo Co., Ltd., pyropet; diameter 2.5 mm, length 4)
(3) PAI: polyamide imide resin (Production Examples 1-2) (4) Glass fiber: (manufactured by Asahi Fiber Co., Ltd .; diameter 10 μm,
3mm length short fiber)

As is clear from the experimental results shown in Table 1, when the polyamide-imide resin granules were used (Examples 1 to 3), the polyamide-imide resin powder was used (Comparative Examples 1 to 3). 3), the extrusion amount is large and the extrusion efficiency is excellent, and the variation of the extrusion amount is small (discharge unevenness is small).

[0053]

According to the present invention, in a method of melting and kneading a polyamide-imide resin and another thermoplastic resin into pellets, the polyamide-imide resin is excellent in handleability and excellent in supply stability to an extruder. A method for producing a resin composition pellet capable of efficiently producing a pellet is provided. The resin composition pellets of the present invention can be formed into various molded products by injection molding or extrusion molding.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int. Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 67/02 C08L 67/02 79/08 79/08 C 81/02 81/02 101/00 101/00 // B29K 79:00 B29K 79:00 (72) Inventor Kiyomi Ouchi 16 Nishikicho Ochiai, Iwaki-shi, Fukushima Kureha Chemical Industry Nishiki Research Laboratory Co., Ltd. F-term (reference) 4F070 AA47 AA55 AA58 AC28 AD04 DA12 DA41 4F201 AA24 AA34 AA40 AC04 BA02 BC01 BC12 BC19 BD05 BL08 BL50 4J002 BB03X BB12X BC03X BD04X BD10X BD12Y BD14X BD15X BF02X BG04X BG05Y BG06X BL02X BN15X CB00146 DE00X CE00X CF00Y CF06X CF07X CF01 CL03 CH03X CG01X CHXX DE236 DG046 DG056 DJ006 DJ016 DJ026 DJ046 DJ056 DK006 DL006 FA04Y FA046 FD01Y FD016

Claims (7)

[Claims] 1. A resin composition pellet obtained by melt-kneading a granulated material (A ₁ ) obtained by mechanically granulating a polyamide-imide resin (A) powder and another thermoplastic resin (B) to form a pellet. Production method. 2. The method according to claim 1, wherein the granulated product (A ₁ ) is a solid product obtained by mechanically compressing a polyamide-imide resin (A) powder. 3. The granulated product (A ₁ ) has a weight average particle size of 10
The method according to claim 1, wherein the thickness is not less than 0 μm and not more than 5 mm. 4. During the melt-kneading of the granulated product (A ₁ ) and the thermoplastic resin (B), the filler (C) and, if necessary, other additives (D) are present to form pellets. The manufacturing method according to claim 1, wherein 5. The method according to claim 1, wherein the polyamide-imide resin (A) is a polyamide-imide resin obtained by polycondensing an aromatic tricarboxylic anhydride and diisocyanate in a solvent. 6. The method according to claim 1, wherein the thermoplastic resin (B) is a polyphenylene sulfide resin or a polyethylene terephthalate resin. 7. The production method according to claim 1, wherein 1 to 60% by weight of the granulated product (A ₁ ) and 40 to 99% by weight of the thermoplastic resin (B) are melt-kneaded and pelletized.